\begin{tikzpicture}
  \matrix
  [matrix of nodes,
  nodes in empty cells,
  column sep={2em,between origins},
  nodes={align=left,text width=5em}] (m)
  {
    & \large $a$ & \large\bcancel{y} y\\
    & \large $b$ & \large\bcancel{y} y\\
    & \large $t_1$ & \large \bcancel{n} \large\bcancel{y} n\\\\
    & \large $a$ & \large\bcancel{y} y\\
    & \large $b$ & \large\bcancel{y} y\\
    & \large $c$ & \large\bcancel{y} y\\
    & \large $d$ & \large\bcancel{y} y\\
    & \large $t_2$ & \large \bcancel{n} \bcancel{y} \bcancel{y} n\\
    & \large $t_3$ & \large \bcancel{n} \bcancel{y} n\\
    & \large $t_4$ & \large \bcancel{n} \bcancel{y} n\\
    & \large $x$ & \large \bcancel{y} n\\
  };
  \node [left=of m-2-1.south,xshift=1em] {$\rm B_1$};
  \node [left=of m-8-1.south,xshift=1em] {$\rm B_2$};
  \draw[decorate,decoration={brace,raise=5pt,mirror},thick,xshift=1em] (m-1-2.north west) -- (m-3-2.south west);
  \draw[decorate,decoration={brace,raise=5pt,mirror},thick,xshift=2em] (m-5-2.north west) -- (m-12-2.south west);
  \draw[dashed] (m-1-3.north west) -- (m-12-3.south west);
\end{tikzpicture}